Aperture – wide open

Aperture – “stopped down”

Exposure: A function of…

Aperture

•the amount of light allowed in through thethe lenslens

Shutter Speed

•the duration (in seconds) of light exposuresure onon the film

Film “Speed”

•sensitivity of the film to light

•(ISO – International Organization for Standardization)

Exposure (cont.)

Aperture

•smaller opening (larger f/#) less lightht

•larger opening (smaller f/#) more lightight

Shutter Speed

•slower permits smaller aperture openingening

•faster need larger aperture opening

Film Speed

•faster (larger ISO#) needs less lightt

•slower (smaller ISO#) needs more lightlight